The Nuclear Medicine and Medical Physics CORE will provide support in nuclear medicine, medical imaging, dosimetry, immunokinetics, radiochemistry, advanced molecular imaging of stem cells, and immune cells. This CORE is a continuation from prior years of the grant, and has been in continuous operation in support of the Immunology PO1 since 1988. Resources continue to improve and now include advanced animal and human imaging facilities for imaging and experimental studies, Several large grants have provided support for imaging technology development, which have strengthened the support for this immunology PO1 core. These include: the Comprehensive Cancer Center Grant (Varmus, PI);In Vivo Celllular and Molecular Imaging Center P50,(Larson/Blasberg, Co-Pi's) the Biomedical Enginneering Partnership,(Ling, PI) and the Imaging CORE of the Breast PO1, (Larson, PI), and the Gene Therapy Program Project (Sadelain, PI). Projects 1-4 make extensive use of CORE experience and resources in planning and implementing their specific aims. In particular, the CORE will assist project 1 with the imaging and alpha dosimetry of Bismuth- 213 and Actinium-225 decay, including the complex problem of quantifying the effect of a branching cascade involving multiple daughters with differing metabolism. For project 2, the CORE will provide quantitative imaging and dosimetry of whole IgG and antibody forms of A-33, based on SPECT of Indium- 111, and PET of Gallium-66, 68 and Yttrium-86. For Project 3, transfected immune cells, especially dendritic cells will be imaged, at the histologic level and possibly non-invasively, with GFP, bioluminescence, or nuclear methodologies. For project 4, transfected bone marrow stem cells will be imaged, using a combination of bioluminescent, GFP and nuclear imaging methodologies, depending on the level of resolution required and the need for quantification.